Absence of food effect on the extent of alprazolam absorption from an orally disintegrating tablet.

STUDY OBJECTIVE: To evaluate the effect of a standardized meal on the bioavailability of alprazolam formulated as an immediate-release orally disintegrating tablet (ODT) in healthy volunteers. DESIGN: Single-dose, randomized, open-label, two-period crossover study. SETTING: Contract research organization clinic. SUBJECTS: Sixteen healthy volunteers (seven men, nine women), aged 20-50 years. Intervention. Subjects were administered a single dose of alprazolam ODT 1.0 mg during two treatment periods-under fasting conditions and after a standard high-fat breakfast-separated by a 7-day washout period, MEASUREMENTS AND MAIN RESULTS: Blood samples for determination of alprazolam pharmacokinetics were collected by venipuncture up to 72 hours after dosing. A validated liquid chromatography with tandem mass spectrometry detection method was used to quantify the alprazolam plasma concentration. The overall extent of alprazolam absorption from the ODT formulation, as measured by area under the concentration-time curve, was unaffected during fed conditions. However, the rate of alprazolam absorption was slower after administration during fed relative to fasted conditions. The mean maximum observed plasma concentration (Cmax) decreased approximately 25%, and time to Cmax (Tmax) was delayed approximately 1.5 hours when food was administered before dosing. CONCLUSION: Coadministration of food was shown to have no effect on extent of absorption of immediate-release alprazolam ODT 1.0 mg when compared with drug administration in the fasted condition; however, the rate of drug absorption was decreased. The clinical significance of the difference in rate of alprazolam absorption is unknown but thought to be minimal.

Bioavailability of lansoprazole granules administered in juice or soft food compared with the intact capsule formulation.

BACKGROUND: The ability to administer the contents of an encapsulated-dose formulation in liquids or soft foods without compromising drug bioavailability is highly desirable for patients who are unable to swallow or have difficulty swallowing. OBJECTIVE: The purpose of this study was to compare the bioavailability of lansoprazole granules administered in 2 types of juice and a soft food with that of the intact capsule administered with water. METHODS: Healthy adult volunteers were eligible for this single-center, Phase I, single-dose, randomized, open-label, 4-period crossover study. Subjects received the enteric-coated granular contents of a 30-mg lansoprazole capsule in 3 test regimens (in 180 mL of orange juice, 180 mL of tomato juice, or 1 tablespoon of strained pears, each followed by 180 mL of water) and 1 reference regimen (the 30-mg intact capsule with 180 mL of water). The regimens were rotated at > or = 6-day intervals so that each subject received all 4 regimens. Blood samples for pharmacokinetic analyses were obtained during the 12 hours after each regimen. RESULTS: Twenty healthy adult volunteers (10 men, 10 women; mean age, 36 years [range, 19-53 years]) completed this study. Bioavailability of the 3 test regimens was assessed using the two 1-sided tests procedure for mean maximum plasma concentration and area under the plasma concentration-time curve (AUC) from time 0 through the last measurable concentration and AUC from time 0 to infinity. These results were compared with that of the intact capsule. This comparison indicated that the 90% CIs for all 3 test regimens were within the acceptable bioequivalence range of 0.80 to 1.25. Lansoprazole was well tolerated, with most of the adverse events being mild. Headache was the most frequently reported adverse event. CONCLUSION: The results of this study indicate that the bioavailability of lansoprazole granules, when administered in orange juice, tomato juice, or a small amount of strained pears, was similar to that of the intact capsule in these healthy adult volunteers.

Pharmacokinetics of intravenous conivaptan in subjects with hepatic or renal impairment.

BACKGROUND: Conivaptan is a non-peptide dual antagonist of vasopressin V1A and V2 receptors that is approved in the United States as an intravenous formulation for the treatment of euvolemic and hypervolemic hyponatremia in hospitalized patients. The pharmacokinetics of intravenous conivaptan had not been studied in patients with hepatic or renal impairment. OBJECTIVE: The objective of this study was to assess the pharmacokinetics and tolerability of intravenous conivaptan in subjects with mild or moderate hepatic or renal impairment compared with subjects with normal function. STUDY DESIGN: These studies were phase I, open-label pharmacokinetic studies conducted at two sites in the US. PATIENTS: Men and non-pregnant women 30-70 years of age were allocated to the mild (Child-Pugh classification score of 5-6) or moderate (Child-Pugh classification score of 7-9) hepatically impaired groups (n = 8-9 per group) based on their liver function assessed at screening. For the renal study, men and non-pregnant women between 18 and 70 years of age were assigned to renal function groups (n = 8-9 per group) based on estimated glomerular filtration rate (eGFR) assessed at screening. Normal renal function was defined as an eGFR >80 ml/min, mild renal impairment as 50-80 ml/min, and moderate renal impairment as 30-49 ml/min. Subjects with normal hepatic or renal function were selected to match the race, sex, age, and body mass index of subjects enrolled in the impaired groups. INTERVENTION: Subjects were administered a 20-mg/30-min intravenous loading dose of conivaptan on day 1, followed by a 20-mg/23.5-h continuous conivaptan infusion. On day 2, immediately following the end of the day 1 infusion, a 20-mg/24-h continuous conivaptan infusion was administered. MAIN OUTCOME MEASURE: Primary pharmacokinetic parameters estimated were the area under the plasma conivaptan concentration-time curve from time 0 to infinity (AUC∞), plasma conivaptan concentrations at the end of the 20-mg loading dose (C LD), and plasma conivaptan concentrations at the end of the second day 20-mg/24-h continuous infusion (C 48). RESULTS: For each of C LD, C 48, and AUC∞, the mean values were similar for subjects with mild hepatic impairment and subjects with normal hepatic function. Subjects with moderate hepatic impairment had a 73 % higher C 48 and an 80 % higher AUC∞ compared with subjects with normal hepatic function. There were no clinically relevant changes in conivaptan exposure in the mild and moderate renal impairment groups compared with subjects with normal renal function. Intravenous conivaptan was generally well tolerated in subjects with mild or moderate hepatic or renal impairment. Infusion-site reaction was the most commonly reported adverse event. CONCLUSION: Overall exposure to conivaptan increased in subjects with moderate hepatic impairment compared with subjects with normal hepatic function. Therefore, in patients with moderate hepatic impairment, conivaptan should be initiated with a loading dose of 10 mg over 30 min followed by 10 mg per day as a continuous infusion for 2-4 days, which is half the approved dose. No dose adjustment is necessary in patients with mild or moderate renal impairment and in patients with mild hepatic impairment.